Sokora Refugees

Kana is a young schoolgirl who has no boyfriend, she has trouble keeping up her schoolwork, and her body has not developed as have the bodies of the other girls.

Matters become rather complicated for her when a being from another dimension (filled with goblins and the like) ends up on earth and in her class. Through the type of mixup that seems Kana's fate, she ends up in that world for a time.

Which, itself, might not be that bad except that an elven sorceress who has been severely injured decides to sort of hitchhike a ride in Kana's body. When that happens she has the fully-developed body of a grown woman and a variety of other problems.

There's really a lot of stuff going on in this manga and it's really very funny. even the artwork is humorous. Definitely an interesting and enjoyable series.